Michael Akinde <michael(dot)akinde(at)met(dot)no> writes:
> As suggested, I tested a VACUUM FULL ANALYZE with 128MB shared_buffers
> and 512 MB reserved for maintenance_work_mem (on a 32 bit machine with 4
> GB RAM). That ought to leave more than enough space for other processes
> in the system. Again, the system fails on the VACUUM with the following
> error (identical to the error we had when maintenance_work_mem was very
> low.
> INFO: vacuuming "pg_catalog.pg_largeobject"
> ERROR: out of memory
> DETAIL: Failed on request of size 536870912
Are you sure this is a VACUUM FULL, and not a plain VACUUM? I suspect
that it's the latter, and the reason it's failing is that you are
running the postmaster under a ulimit that is less than 512MB (or at
least not enough more to allow an allocation of that size).
regards, tom lane